The relationship between female competition for mates and number of adult males living in social groups was investigated. Subjects were housed in 3 social groups in 1/4 acre outdoor corrals. Affiliative, sexual, and agonistic behaviors were recorded from August 1995 to June 1996 (452.5 hours). Data were analyzed using 3-way ANOVA with repeated measures. Female access to mates was not associated with social rank, but indicated active female competition for mates in the muli-male groups. Females in multi-male groups had more frequent affiliative and sexual interactions per adult male than females in the one-male group, and the frequency of females' agonistic interactions with juvenils and adult females was positively correlated with the number of adult males present in the social group during the breeding season. Higher competition between females could be interpreted as the result of both male and female reproductive strategies Female competition for mates is enhanced in situations where they could manipulate male competition and choice of mates.